Make clear that server listens on all interfaces

src/main.c

@@ -115,7 +115,7 @@ int main(int argc, char **argv)
         return 1;
     }
 
-    printf("Server is running on http://localhost:%d\n", port);
+    printf("Server is running on http://0.0.0.0:%d\n", port);
 
     // Keep the server running
     getchar();